1. Field of the Invention
The invention generally relates to patterning of polymeric materials. More specifically, the invention relates to light based patterning methods.
2. Description of the Relevant Art
Optical lithography techniques are currently used to alter topographies of many different surfaces. For example, sub-micron scale lithography has been a critical process in the microelectronics industry. Other applications of nanometer scale lithography exist in the areas of opto-electronics and magnetic storage. For example, photonic crystals and high-density patterned magnetic memory of the order of terabytes per square inch may require sub-100 nanometer scale lithography.
For making sub-50 nm structures, optical lithography techniques may require the use of very short wavelengths of light (e.g., about 13.2 nm). Such processes lead to extremely complicated equipment and techniques that may be prohibitively expensive. It is also believed that high-resolution e-beam lithography techniques, though very precise, are too slow for high volume commercial applications.
Several imprint lithography techniques have been investigated as low cost, high volume manufacturing alternatives to conventional photolithography for high-resolution patterning. Imprint lithography techniques are similar in that they use a template containing topography to replicate a surface relief in a film on the substrate.
Techniques such as electrohydrodynamic patterning (EHP) of polymers and photopolymerizable liquids, lithographically induced self-assembly (LISA), and lithographically induced self-construction (LISC), have previously been used to create topographic features in polymer films. These techniques are driven by physical forces created when a mask is placed in close proximity to the polymer during thermal processing of the polymer. The requirement of a mask during this step, inherently limits the throughput of these techniques.
It is desirable to develop alternative techniques to photolithography and imprint lithographic techniques that are low cost and capable of being used in high throughput applications.